Tuesday, 7 July 2015

Human error is now the leading cause of plane crashes, and one of the principal factors that provokes pilots to make mistakes is stress. Some pilots cope heroically in the face of stress, such as Chesley Sullenberger who steered his plane and passengers to safety, landing on the Hudson river after a double engine failure. Others fare less well, with sometimes fatal results. Knowing in advance how pilots will respond to stressful situations is therefore of paramount of importance to flight safety – for example, to indicate whether they need more training.

A new study reports that, more than relevant facts such as age and years of experience, pilots' answers to two simple questions can more accurately forecast how they will respond to a stressful situation.

Samuel Vine and his colleagues recruited 16 experienced commercial airline pilots (average age 35; two women) to complete a Bombardier Dash 8 flight simulator exercise. After they readied the plane for take-off, the pilots were told that the exercise would involve an engine failure occurring shortly after take off (widely considered one of the most stressful situations a pilot can face) and their task would be to land the plane safely. It was at this point that the two key questions were posed to the pilots:

"How demanding do you expect the task to be?"

"How able are you to cope with the demands of the task?"

The pilots scored their answer to each question on a scale of 1 (not at all) to 6 (extremely). The difference between the two provided a single measure of whether the pilots interpreted the forthcoming emergency as a challenge (when coping ability outweighs demands) or a threat (coping ability insufficient for the demands).

The important finding was that this single measure accurately predicted how well the pilots subsequently coped with the engine failure during the flight simulation. Pilots who rated the upcoming situation as more of a threat tended to perform worse than those who rated it more as a challenge.

This was true whether the pilots' performance was judged subjectively by a flight instructor (who was naive as to the aims of the study) or through objective measures of aircraft control, such as the speed and heading of the plane and the pilots' gaze (in terms of how much they looked where they should on the control panel).

Moreover, the these two simple questions predicted the pilots' coping abilities above and beyond other relevant factors such as age and years of experience. After age and experience were accounted for, the threat/challenge score explained 61 per cent of the variance on the instructor's subjective ratings of performance and 33 per cent of the variance in the heading of the plane. Further analysis showed that one of the key ways that a threat response adversely affected the pilots' handling of the plane was through its effect on their gaze: specifically, a threat reaction was associated with more fixations overall, and looking in the wrong places.

The study isn't perfect – of course it relied on a flight simulator for one thing – but the results are important. They have "implications for safety and error avoidance in safety critical industries (e.g. aviation, surgery, and driving) and for improved performance in stressful applied environments (e.g. sport and military)," the researchers concluded, "... the current study provides further support for the validity of expedient self-report measures that can be easily collected in applied environments."